Hi, I'm having an issue at the moment with power going up and down with my LGU. For example every few dozen shots I might get a few shots dropping out of kill at 50+ yds. Sometimes it's a couple, sometimes it's half a dozen. On a course this is not great as it's enough to start compensating by aiming high or adding clicks, only to have it go back to normal a few shots later and they start going high. I have a fairly speculative theory that it may be due to the rotating piston. If the comp tube is slightly out of round and the piston is able to rotate, there may be a little more friction at one spot. The piston moves round gradually and every so often a bearing hits a tighter spot, power drops, but then moves past and power goes back to normal. Fairly sure it's not the pellets as I've shot this batch of AA 8.4 for 18 months and they've been spot on. I'm going to clean the barrel and re-lead just to rule out a dirty barrel. I haven't ruled out lube yet either but I was curious if this is a thing. I wondered if this phenomenon had ever been noticed with other guns with rotating pistons. The other Walthers and the TX/PS.